Presses have for years been utilized to provide cutting, bending, forming and other basic manufacturing operations on parts of small sizes and large sizes sufficient to be inserted between the crown and press bed. While innovations to hydraulic presses have been legion throughout the years because of the versatility of presses in manufacturing operations, persons and entities involved in manufacturing operations in addition to developing numerous dies for use in the process, have developed numerous apparatus for moving material to be operated on in the press into and out of the position at which the press operations take place. Additionally, applicant has been involved in inventing protective rocker-arm safety devices for presses as shown in U.S. Pat. No. 4,161,140.
When the product parts are substantially smaller than the opening between the press dies, it is typical to have these parts formed in row-column order on a sheet of material that is passed through the press. The press then stamps, cuts, forms or performs other operations on multiple ones of those parts as each individual part is a discrete segment of that sheet of material. Typically, a sheet of such material that is to be formed into parts is positioned on a movable platen by manual or robotic means, or by transfer of the part from one platen to another in a line or series of presses performing differing operations on the parts to be manufactured. Various press transfer apparatuses have typically included linkages having bell cranks to turn rotary motion into linear motion as shown in U.S. Pat. No. 4,651,866. Screw mechanisms have heretofore been utilized to move platens horizontally into and out of position in presses as shown in U.S. Pat. No. 5,749,290. Parallel linkages have also been utilized to feed material to and through presses and/or equipment for machining operations, as shown in U.S. Pat. No. 5,078,570.
In a prior generation of applicant's presses, sheets of plastic and/or rubber material were positioned on a platen which was moved into position into and over the lower die mounted on the press. In order to conserve energy and motion, the platen was hinged at its far end to a screw drive type feed mechanism and, at the near end of the sheet, the platen was raised and lowered as necessary to put the desired portion of the sheet into the correct spatial zone between the upper and lower dies. This mechanical pivoting of the platen and screw drive horizontal location of the platen provided satisfactory results for then current technology finishing operations in the press. Linear motors have been utilized in machine tool operations and in other manufacturing operations as shown in U.S. Pat. Nos. 5,225,725 and 5,808,382.
A need has developed for more accurate positioning of products with respect to the dies in a commercial press. Additionally, a need has arisen to more accurately move a sheet product into a position between the dies of a press to allow manufacturing operations to be undertaken to the sheet of material in a more accurate manner than heretofore known.
It is therefore and object of the present invention, generally stated, to provide new and improved apparatus for moving product into and out of a position in a press where operations may be performed on that product.
It is a further object of the present invention to provide more accurate means of moving a sheet product vertically with respect to a press than heretofore known.
It is a further object of the present invention to provide improved means for moving a sheet product longitudinally with respect to a press than heretofore known.